Systems and methods for monitoring and controlling use of medical devices

ABSTRACT

A usage key card is adapted to be handled separate from a device tissue treatment device. The usage key card has a storage medium formatted to contain an identification code, which is unique to the usage key card. The usage key card is also adapted to be read by a reader separate from the device. The storage medium is also formatted, when inserted into the reader, to retain data generated pertaining to operation of the device.

RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.10/974,454, filed Oct. 27, 2004 now U.S. Pat. No. 7,465,301, which is adivisional of U.S. patent application Ser. No. 09/974,750, filed Oct.10, 2001 (now U.S. Pat. No. 6,827,713), which is a continuation of U.S.patent application Ser. No. 09/495,390, filed Jan. 30, 2000, andentitled “Systems and Methods for Monitoring and Controlling Use ofMedical Devices,” now abandoned.

FIELD OF THE INVENTION

The invention is directed to systems and methods for monitoring andcontrolling use of medical devices.

BACKGROUND OF THE INVENTION

Use of medical devices intended to treat or diagnose conditions of thebody can sometimes generate stress on the material or materials fromwhich the devices are made. The material stress can alter the physicalcharacteristics of the devices., making future performance of thedevices unpredictable.

In addition, exposure to blood and tissue during use can entrapbiological components on or within many medical devices. Despitecleaning and subsequent sterilization, the presence of entrappedbiological components can lead to unacceptable pyrogenic reactions.

The effects of material stress and damage caused during a single use ofa medical device, coupled with the possibility of pyrogen reactions evenafter resterilization, reasonably justify imposing a single userestriction upon many medical devices.

SUMMARY OF THE INVENTION

The invention provides systems and methods for monitoring andcontrolling use of medical devices.

One aspect of the invention provides a kit containing a device fortreating a tissue region. The kit also includes, packaged with thedevice, a usage key card. The usage key card comprises a storage medium,which is formatted to contain an identification code unique to the usagekey card. The usage key card is adapted to be read by a remote reader,to download the identification code for processing by a controller forthe device. Preestablished prior use criteria govern the processing ofthe identification code by the controller. Meeting the criteria permitsoperation of the device, conversely, not meeting the criteria disablesuse of the device.

In one embodiment, the storage medium is also formatted to retain datagenerated by the controller during permitted operation of the device.The data, e.g., pertains to operating conditions of the device, creatinga procedure log. In this arrangement, the usage key card is adapted tobe read by a reader, to download the procedure log for furtherprocessing by a separate data processing device.

Another aspect of the invention provides systems and methods forprocessing the identification code by the controller. The systems andmethods cause the controller to create a table in memory in which unlikeidentification codes are registered as they are downloaded by thereader. The systems and methods enable operation of the device when anew identification code is registered in the table.

According to this aspect of the invention, the systems and methods causethe controller to compare a given identification code downloaded by thereader to all identification codes registered in the table. The systemsand methods cause the controller to register the given identificationcode in the table when the given identification code does not match anyidentification code in the table. In this instance, operation of thedevice is permitted. Conversely, the systems and methods cause thecontroller not to register the given identification code when the givenidentification code matches an identification code already in the table.In this instance, operation of the device is not permitted.

In an embodiment that pertains to both aspects of the invention, thedevice operates to apply radio frequency energy to the tissue region.

Features and advantages of the inventions are set forth in the followingDescription and Drawings, as well as in the appended Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a system for treating body sphinctersand adjoining tissue regions, which embodies features of the invention;

FIG. 2 is a perspective view, with portions broken away, of a deviceusable in association with the system shown in FIG. 1 having anoperative element for contacting tissue shown in a collapsed condition;

FIG. 3 is a perspective view, with portions broken away, of the deviceshown in FIG. 2, with the operative element shown in an expandedcondition;

FIG. 4 is a perspective view, with portions broken away, of the deviceshown in FIG. 2, with the operative element shown in an expandedcondition and the electrodes extended for use;

FIG. 5 is an enlarged view of the operative element shown in FIG. 4,with the electrodes extended for use;

FIG. 6 is a perspective view of a kit containing a device, such as shownin FIGS. 2 to 5, and a usage key card;

FIG. 7 is an enlarged, mainly schematic view of the usage key card shownin FIG. 6, embodied as a floppy disk, and also showing the pre-formatedfiles it contains;

FIG. 8 is a schematic view of a controller, which the system shown inFIG. 1 incorporates, showing the pre-programmed rules by whichinformation contained on the usage key card shown in FIGS. 6 and 7 isread and processed; and

FIG. 9 is a schematic view of another processing device that readsinformation from the usage key card for further processing.

The invention may be embodied in several forms without departing fromits spirit or essential characteristics. The scope of the invention isdefined in the appended claims, rather than in the specific descriptionpreceding them. All embodiments that fall within the meaning and rangeof equivalency of the claims are therefore intended to be embraced bythe claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows one embodiment of a system 10, which monitors and controlsthe use of an operative element 12. The system 10 is well adapted forassociation with single use, catheter-based devices. Therefore, in theillustrated embodiment, the operative element 12 is part of acatheter-based treatment device 26. It should be appreciated, however,that the system 10 is also adaptable for use with devices and methodsthat are not necessarily catheter-based.

A. The Treatment Device

In the illustrated embodiment, the device 26 includes a handle 28 made,e.g., from molded plastic. The handle 28 is sized to be convenientlyheld by a physician, to introduce the catheter tube 30 into the targetedtissue region.

The handle 28 carries a flexible catheter tube 30. The catheter tube 30can be constructed, for example, using standard flexible, medical gradeplastic materials. The catheter tube 30 has a distal end 34, whichcarries the operative element 12.

The operative element 12 can support, for example, a device for imagingbody tissue, such as an endoscope, or an ultrasound transducer. Theoperative element 12 can also support a device to deliver a drug ortherapeutic material to body tissue. The operative element 12 can alsosupport a device for sensing a physiological characteristic in tissue,such as electrical activity, or for transmitting energy to stimulate orform lesions in tissue.

In the illustrated embodiment, the device 26, in use, is intended totreat dysfunction of sphincters and adjoining tissue regions in theupper gastrointestinal tract, e.g., in the lower esophageal sphincterand adjacent cardia of the stomach, as well as in the lowergastrointestinal tract, e.g., in the intestines, rectum and anal canal.Still, it should be appreciated that the system 10 can be used inassociation with other devices and methods used to treat otherdysfunctions elsewhere in the body, which are not necessarilysphincter-related. For example, the various aspects of the inventionhave application in procedures requiring ablation of tissue throughoutthe body, or treatment of hemorrhoids, or restoring compliance to orotherwise tightening interior tissue or muscle regions.

In the illustrated embodiment, one function that the operative element12 is to perform is to apply energy in a selective fashion to a targetedbody region, which, for the purpose of illustration, can be the loweresophageal sphincter, or cardia, or both. The applied energy creates oneor more lesions, or a prescribed pattern of lesions, below the mucosalsurface of the esophagus or cardia. The subsurface lesions are formed ina manner that preserves and protects the mucosal surface against thermaldamage.

It has been discovered that natural healing of the-subsurface lesionsleads to a physical tightening of the sphincter and/or adjoining cardia.The subsurface lesions can also result in the interruption of aberrantelectrical pathways that may cause spontaneous sphincter relaxation. Inany event, the treatment can restore normal closure function to thesphincter.

The structure of the operative element 12 to achieve this result canvary. A representative embodiment is shown in FIGS. 2 to 4, in which theoperative element 12 comprises a three-dimensional basket 56. The basket56 includes one or more spines 58, and typically includes from four toeight spines 58, which are assembled together by a distal hub 60 and aproximal base 62.

In the illustrated embodiment, an expandable structure 72 comprising aballoon is located within the basket 56. The balloon structure 72 can bemade, e.g., from a Polyethylene Terephthalate (PET) material, or apolyamide (non-compliant) material, or a radiation cross-linkedpolyethylene (semi-compliant) material, or a latex material, or asilicone material, or a C-Flex (highly compliant) material.

The balloon structure 72 presents a normally, generally collapsedcondition, as FIG. 2 shows. In this condition, the basket 56 is alsonormally collapsed about the balloon structure 72, presenting a lowprofile for deployment into the esophagus 10.

The catheter tube 30 includes an interior lumen, which communicates withthe interior of the balloon structure 72. A fitting 76 (e.g., asyringe-activated check valve) is carried by the handle 28. The fitting76 communicates with the lumen. The fitting 76 couples the lumen to asyringe 78 (see FIG. 3). The syringe 78 injects fluid under pressurethrough the lumen into the balloon structure 72, causing its expansion.

Expansion of the balloon structure 72 urges the basket 56 to open andexpand (see FIG. 3). The force exerted by the balloon structure 72, whenexpanded, is sufficient to exert an opening force upon the tissuesurrounding the basket 56.

Each spine 58 carries an electrode 66 (see FIG. 4). In the illustratedembodiment, each electrode 66 is carried within the tubular spine 58 forsliding movement. Each electrode 66 slides from a retracted position,withdrawn in the spine 58 (shown in FIG. 3) and an extended position,extending outward from the spine 58 (see FIG. 4) through a hole in thespine 58. A push-pull lever 68 on the handle 28 is coupled by one ormore interior wires to the sliding electrodes 66. The lever 68 controlsmovement electrodes between the retracted position (by pulling rearwardon the lever 68) and the extended position (by pushing forward on thelever 68). The electrodes 66 have sufficient distal sharpness andstrength, when extended, to penetrate a desired depth into tissue thesmooth muscle of the esophageal or cardia 20 wall. The desired depth canrange from about 4 mm to about 5 mm.

In this arrangement (see FIG. 1), the system 10 includes a generator 38to supply the treatment energy to the electrodes 66. In the illustratedembodiment, the generator 38 supplies radio frequency energy, e.g.,having a frequency in the range of about 400 kHz to about 10 mHz. Ofcourse, other forms of energy can be applied, e.g., coherent orincoherent light; heated or cooled fluid; resistive heating; microwave;ultrasound; a tissue ablation fluid; or cryogenic fluid.

A cable 40 extending from the proximal end of the handle 28 terminateswith an electrical connector 42. The cable 40 is electrically coupled tothe operative element 12, e.g., by wires that extend through theinterior of the handle 28 and catheter tube 30. The connector 42 plugsinto the generator 38, to convey the generated energy to the operativeelement 12.

The electrodes 66 are formed of material that conducts radio frequencyenergy, e.g., nickel titanium, stainless steel, e.g., 304 stainlesssteel, or a combination of nickel titanium and stainless steel.

In the illustrated embodiment (see FIG. 5), an electrical insulatingmaterial 70 is coated about the proximal end of each electrode 66. Whenthe distal end of the electrode 66 penetrating the smooth muscle of theesophageal sphincter 18 or cardia 20 transmits radio frequency energy,the material 70 insulates the mucosal surface of the esophagus 10 orcardia 20 from direct exposure to the radio frequency energy. Thermaldamage to the mucosal surface is thereby avoided. The mucosal surfacecan also be actively cooled during application of radio frequencyenergy, to further protect the mucosal surface from thermal damage.

In the illustrated embodiment (see FIG. 5) at least one temperaturesensor 80 is associated with each electrode. One temperature sensor 80senses temperature conditions near the exposed distal end of theelectrode 66, a second temperature sensor 80 is located on thecorresponding spine 58, which rests against the muscosal surface whenthe balloon structure 72 is inflated.

The system 10 (see FIG. 1) can also include certain auxiliary processingequipment, e.g., an external fluid delivery apparatus 44 for supplyingcooling liquid to the targeted tissue, e.g., through holes in thespines, and an external aspirating apparatus 46 for conveying liquidfrom the targeted tissue site, e.g., through other holes in the spine orelsewhere on the basket 56.

The system 10 also includes a controller 52. The controller 52, whichpreferably includes a central processing unit (CPU), is linked to thegenerator 38, the fluid delivery apparatus 44, and the aspiratingapparatus 46. Alternatively, the aspirating apparatus 46 can comprise aconventional vacuum source typically present in a physician's suite,which operates continuously, independent of the controller 52. Thecontroller 52 governs the delivery of processing fluid and, if desired,the removal of aspirated material.

The controller 52 also governs the power levels, cycles, and durationthat the radio frequency energy is distributed to the electrodes 66, toachieve and maintain power levels appropriate to achieve the desiredtreatment objectives. The controller 52 can condition the electrodes 66to operate in a monopolar mode. In this mode, each electrode 66 servesas a transmitter of energy, and an indifferent patch electrode (notshown) serves as a common return for all electrodes 66. Alternatively,the controller 52 can condition the electrodes 66 to operate in abipolar mode. In this mode, one of the electrodes comprises thetransmitter and an other electrode comprises the return for thetransmitted energy. The bipolar electrode pairs can electrodes 66 onadjacent spines, or electrodes 66 spaced more widely apart on differentspines.

The controller 52 includes an input/output (I/O) device 54. The I/Odevice 54 allows the physician to input control and processingvariables, to enable the controller to generate appropriate commandsignals. The I/O device 54 also receives real time processing feedbackinformation from the temperature sensors 80, for processing by thecontroller 52, e.g., to govern the application of energy and thedelivery of processing fluid. The I/O device 54 also includes agraphical user interface (GUI), to graphically present processinginformation to the physician for viewing or analysis.

B. Monitoring and Control of Reuse

The handle 28 and the catheter tube 30 form an integrated constructionintended for a single use and subsequent disposal as a unit.Alternatively, the handle 28 can comprise a nondisposable componentintended for multiple uses. In this arrangement, the catheter tube 30,and components carried at the end of the catheter tube 30 comprise adisposable assembly, which the physician releasably connects to thehandle 28 at time of use and disconnects and discards after use. Thecatheter tube 30 can, for example, include a male plug connector thatcouples to a female plug receptacle on the handle 28.

To protect patients from the potential adverse consequences occasionedby multiple use, which include disease transmission, or material stressand instability, or decreased or unpredictable performance, thecontroller 54 includes a module 48 that controls use of the device 26.

In the illustrated embodiment (see FIG. 6), the device 26 is supplied aspart of a kit 200 that includes, together with the device 26, a usagekey card 202. The kit 200 packages the device 26 and usage key card 202as a unitary, single use item in a sterile fashion within peripherallysealed sheets of plastic film material that are torn or peeled away atthe instance of use.

The presence of the device 26 and user key card 200 packaged together inthe kit 200 verifies to the physician or user that device 26 is sterileand has not be subjected to prior use. The physician or user is therebyassured that the device 26 meets established performance and sterilityspecifications. No unused device 26 is supplied in the kit 200 without ausage key card 202, and vice versa.

The usage key card 202 incorporates a storage medium 204 that isreadable by the module 48. The storage medium 204 contains informationthat enables at least two use control and monitoring functions.

The first use control and monitoring function of the usage key card 202occurs prior to use of the device 26 in association with the generator38. To enable use of the generator 38 in association with the device 26,the physician must first present the usage key card 202 for reading bythe module 48. To enable use of the device 26, the controller 54 mustthen find that the usage key card 202 meets the criteria necessary forits registration by the controller 54. The criteria are designed toindicate the absence of a prior use, either in absolute terms or interms of a period of use outside a predetermined time period. If thecriteria are not met, the controller 54 will not register the usage keycard 202, and the controller 54 will also not enable use of thegenerator 38 in association with the device 26. Further details of theregistration function of the controller 54 will be described later.

The second use control and monitoring function of the usage key card 202occurs if the criteria are met and registration of the usage key card202 occurs. During permitted use of the device 26 in association withthe generator 38, the storage medium 204 of the usage key card 202remains in the module 48 and receives, via the module 48, data generatedby the controller 54 recording operating parameters and performance ofthe device 26. The storage medium 204 of the usage key card 202 retainsand organizes the data for further off-line storage and processing.Further details of the data retention function will be described later.

The usage key card 202 can be variously configured. In the illustratedembodiment (see FIG. 7), the usage key card 202 comprises acomputer-readable storage medium 204 housed within a conventional 3.5inch floppy disk 206. In this arrangement, the module 48 comprises aconventional floppy disk drive 208 (see FIG. 8) capable of reading datafrom and downloading data to the storage medium 204 of the disk 206.

Alternatively, the usage key card 202 can take the form of a PC card,flash memory device, or magnetic card. In these alternative embodiments,the module 48 comprises a data reading and writing device compatiblewith the storage medium of the card 202.

As FIG. 7 shows, the storage medium 204 of the usage key card 202contains at least two pre-formatted files 210 and 212. The first file210 contains a unique identification code 214 capable of being read bythe module 48 and registered by the controller 54. The second file 212is formatted to receive and retain operational and performance datagenerated by the controller 54 to create from it a procedure log 220.

The identification code 214 contained in the first file 210 is createdto be unique to the particular usage key card 202. That is, each usagekey card 202 contains its own unique identification code 214. No twousage key cards share the same identification code 214. The uniqueidentification code 214 can comprise, e.g., a serial number uniquelyassigned to the particular device 26 found in the kit 200, or any otherunique code that is not repeated for any other usage key card 202. Thecode 214 itself can comprise letters, numbers, or combinations thereof.

As FIG. 8 shows, the module 48 reads the identification code 214 off theusage key card 202 for input to the controller 54. This identificationcode will be called the “instant identification code.”

Following pre-programmed rules, the controller 54 constructs andmaintains in non-volatile memory a use table 216. The use table 216contains all prior identification codes that meet the criteria to beregistered by the controller 54. These identification codes will becalled the “registered identification codes.” Following pre-programmedrules, the controller 54 compares the instant identification code 214 toall registered identification codes contained in the table 216. In theabsence of a match between the instant identification code and anyregistered identification code, the controller 54 updates the table,i.e., the controller registers the instant identification code by addingit to the table 216. Upon registering the usage key card 202, thecontroller 54 also enables use of generator 38 in association with thedevice.

The presence of a match between the instant identification code and anyregistered identification code indicates the usage key card 202 has beenpreviously read by the module 48, which reflects a prior use of thedevice 26 or another device not packaged with the card 202. In thiscircumstance, the controller 54 does not add the duplicativeidentification code to the table 216 and does not enable use of thegenerator 38 in association with any device 26. Preferably, thecontroller 54 outputs to the GUI notice of prior use.

In an alternative arrangement, the controller 54 maintains for eachregistered identification code in the table 216 a time record 218. Thetime record 218 contains a value reflecting the period of time duringwhich energy was applied by the generator 38 during the previouspermitted use. In this embodiment, when a match occurs between theinstant identification code and a registered identification code, thecontroller 54 ascertains whether the time period of previous usecontained in the record 218 is less than a prescribed maximum timeperiod, e.g., 45 minutes. If so, the controller 54 enables a subsequentoperation of the generator 38 in association with the device 26, butonly for the time period remaining. The controller 54 updates the timerecord 218 as further use occurs. The controller 54 preferably outputsto the GUI the time period of permitted use remaining.

If the controller 54 ascertains that the time period of previous useequals or exceeds the prescribed maximum time period, the controller 54does not enable use of the generator 38. Preferably, the controller 54outputs to the GUI notice of prior use.

As FIG. 9 shows, the second file 212 contained on the storage medium 204of the usage key card 202 is formatted to receive, via the module 48,data that is generated by the controller 54 during permitted use of thedevice 26 in association with the generator 38. The file 212 retains thedata in a formatted array according to pre-programmed rules to create aprocedure log 220.

The content of the formatted log 220 can vary. For example, the log 220can document, by date of treatment and number of treatments, thecoagulation level (i.e., the depth at which the electrodes areinserted), the time duration of energy application, the magnitude ofenergy delivered by each electrode, and the coolant flow rate. Theprocedure log 220 can also record at pre-established intervals (e.g.,every 5 seconds) the temperatures of the electrodes and surroundingtissue, along other parameters e.g., sensed impedance and powerdelivered by each electrode. The procedure log 220 preferably recordsthese values in a pre-formatted data base format, to enable import ofthe values as data base items for storage, processing1 and retrieval byan off-line data processing device 222 having a compatible data baseprocessing application. The off-line data processing device 222 readsprocessing log data from the usage key card 202 (via a floppy disk drive230 or otherwise compatible reading device).

The device 222 can process the data in various ways according to therules of the data processing application. The device 222 can, e.g.,create a print-formatted record of the procedure log 220 for printing ina hard copy version. The device 222 can also, e.g., process theprocedure logs for multiple devices and patients, to create historicalpatient treatment records, patient reimbursement records, and the likefor storage or retrieval. The device 222 thereby makes possible theestablishment and maintenance of an archival patient data base byprocessing individual procedure logs.

As FIG. 6 shows, the kit 200 can also include a label 224 that ispre-applied or that can be applied by the physician to the usage keycard 202. The label 224 receives manually transcribed, visually readableinformation pertaining to the usage key card 202, e.g., the name of thepatient being treated by the device 26, the date of treatment, and thelike. In this way, usage key cards 202 can itself be physically storedand indexed.

As FIG. 6 also shows, the kit 200 can also include instructions 232 forusing the usage key card 202 in the fashion described. For example, theinstructions 232 can instruct the physician as to the need for havingthe usage key card 202 read by the module 48, in order to enable use ofthe device 26 in association with the generator 38. The instructions 232can also instruct the physician regarding the content of the procedurelog and the subsequent off-line processing options that are available.

As FIG. 7 shows, the storage medium 204 of the usage key card 202 canalso contain at least one additional formatted file 226 that providesdevice information 228, which characterizes the device 26 supplied inthe kit 200. For example, the device information 228, when read by themodule 48, can identify the type of device 26 in terms of itsoperational characteristics, the inclusion of temperature sensing, andreuse criteria (e.g., no reuse after a single use, or multiple usespermitted up a prescribed maximum number of uses, or multiple usespermitted up to a maximum time period of use, or multiple uses permittedup to a maximum application of RF energy). The file 226 can alsocondition the GUI to display the desired images and data formats, whichchange depending upon the treatment procedure using the device (e.g.treatment of GERD, fecal incontinence, or urinary incontinence). In onearrangement, the controller 54 can compare the device characteristicswith the operational characteristics of the controller 54 and generator38, and disable operation of the device 26 should the characteristics ofthe device 26 be incompatible with the characteristics of the controller54 and/or generator 38.

Various features of the invention are set forth in the following claims.

We claim:
 1. A system comprising a device for treating a tissue region,and a usage key card not connected to the device to be handled separatefrom the device comprising a storage medium formatted to contain anidentification code uniquely assigned to the device, the identificationcode being unique to the usage key card, the usage key card beingadapted to be read by a reader separate from the device, the storagemedium being also formatted, when inserted into the reader, to retaindata generated during operation of the device pertaining to operation ofthe device, the reader downloading the identification code to acontroller to update a use table and register the identification code ifnot previously registered upon being downloaded to enable use of thedevice upon being registered.
 2. A system according to claim 1 whereinthe usage key card comprises a floppy disk.
 3. A system according toclaim 1 wherein the usage key card comprises a PC card.
 4. A systemaccording to claim 1 wherein the usage key card comprises a magneticcard.
 5. A system according to claim 1 wherein the usage key cardcomprises flash memory.
 6. A system according to claim 1 wherein thedevice applies radio frequency energy to the tissue region.
 7. A systemaccording to claim 1 wherein when the usage key card is inserted intothe reader and the reader downloads the identification code to thecontroller the use table is not updated if the identification code ispreviously registered.
 8. A system according to claim 1 wherein thestorage medium contains at least first and second pre-formatted files,the first file containing the identification code and the second filecontaining operational and performance data.
 9. A system according toclaim 8 wherein the second file receives data generated by thecontroller during permitted use of the device.
 10. A system according toclaim 9 wherein the second file retains the data in a formatted array tocreate a procedure log.
 11. A system according to claim 10 wherein theprocedure log documents by date of treatment a magnitude of energydelivered by the device.
 12. A system according to claim 10 wherein theprocedure log documents by date of treatment a time duration of energyapplication.
 13. A system comprising a device for treating a tissueregion; and a storage medium associated with the device, the storagemedium formatted to contain an identification code uniquely assigned tothe device, the storage medium adapted to be read by a reader separatefrom the device for downloading the identification code to a controllerto enable the controller to add to its registry the downloadedidentification code if not already in its registry upon being downloadedto enable use of the device upon being added to its registry and to notadd the identification code to its registry if already in its registry.14. A system according to claim 13 wherein the storage medium containsat least first and second pre-formatted files, the first file containingthe identification code and the second file containing operational andperformance data.
 15. A system according to claim 14 wherein the secondfile receives data generated by the controller during permitted use ofthe device.
 16. A system according to claim 15 wherein the second fileretains the data in a formatted array to create a procedure log.
 17. Asystem according to claim 16 wherein the procedure log documents by dateof treatment a magnitude of energy delivered by the device.
 18. A systemaccording to claim 16 wherein the procedure log documents by date oftreatment a time duration of energy application.